// CodeMirror, copyright (c) by Marijn Haverbeke and others
// Distributed under an MIT license: http://codemirror.net/LICENSE

(function(mod) {
  if (typeof exports == "object" && typeof module == "object") // CommonJS
    mod(require("../../lib/codemirror"));
  else if (typeof define == "function" && define.amd) // AMD
    define(["../../lib/codemirror"], mod);
  else // Plain browser env
    mod(CodeMirror);
})(function(CodeMirror) {
  "use strict";

  var HINT_ELEMENT_CLASS        = "CodeMirror-hint";
  var ACTIVE_HINT_ELEMENT_CLASS = "CodeMirror-hint-active";

  // This is the old interface, kept around for now to stay
  // backwards-compatible.
  CodeMirror.showHint = function(cm, getHints, options) {
    if (!getHints) return cm.showHint(options);
    if (options && options.async) getHints.async = true;
    var newOpts = {hint: getHints};
    if (options) for (var prop in options) newOpts[prop] = options[prop];
    return cm.showHint(newOpts);
  };

    CodeMirror.defineExtension("showHint",
        function(options) {
            options = parseOptions(this, this.getCursor("start"), options);
            var selections = this.listSelections();
            if (selections.length > 1)
                return;
            // By default, don't allow completion when something is selected.
            // A hint function can have a `supportsSelection` property to
            // indicate that it can handle selections.
            if (this.somethingSelected()) {
                if (!options.hint.supportsSelection) return;
                // Don't try with cross-line selections
                for (var i = 0; i < selections.length; i++)
                    if (selections[i].head.line != selections[i].anchor.line)
                        return;
            }

            if (this.state.completionActive) this.state.completionActive.close();
            var completion = this.state.completionActive = new Completion(this, options);
            if (!completion.options.hint) return;

            CodeMirror.signal(this, "startCompletion", this);
            completion.update(true);
        });

  function Completion(cm, options) {
    this.cm = cm;
    this.options = options;
    this.widget = null;
    this.debounce = 0;
    this.tick = 0;
    this.startPos = this.cm.getCursor("start");
    this.startLen = this.cm.getLine(this.startPos.line).length - this.cm.getSelection().length;

    var self = this;
    cm.on("cursorActivity", this.activityFunc = function() { self.cursorActivity(); });
  }

  var requestAnimationFrame = window.requestAnimationFrame || function(fn) {
    return setTimeout(fn, 1000/60);
  };
  var cancelAnimationFrame = window.cancelAnimationFrame || clearTimeout;

  Completion.prototype = {
    close: function() {
      if (!this.active()) return;
      this.cm.state.completionActive = null;
      this.tick = null;
      this.cm.off("cursorActivity", this.activityFunc);

      if (this.widget && this.data) CodeMirror.signal(this.data, "close");
      if (this.widget) this.widget.close();
      CodeMirror.signal(this.cm, "endCompletion", this.cm);
    },

    active: function() {
      return this.cm.state.completionActive == this;
    },

    pick: function(data, i) {
      var completion = data.list[i];
        if (completion.hint) {
            completion.hint(this.cm, data, completion);
        }
        else {
            // original to: completion.to || data.to
            var to = this.cm.getCursor();
            this.cm.replaceRange(getText(completion), completion.from || data.from, to, "complete");
        }
      CodeMirror.signal(data, "pick", completion);
      this.close();
    },

    cursorActivity: function() {
      if (this.debounce) {
        cancelAnimationFrame(this.debounce);
        this.debounce = 0;
      }

      var pos = this.cm.getCursor(), line = this.cm.getLine(pos.line);
        // originally also: pos.line != this.startPos.line || line.length - pos.ch != this.startLen - this.startPos.ch || pos.ch < this.startPos.ch 
        if (this.cm.somethingSelected() || (pos.ch && this.options.closeCharacters.test(line.charAt(pos.ch - 1)))) {
            this.close();
        } else {
            var self = this;
            this.debounce = requestAnimationFrame(function() { self.update(); });
            /*if (this.widget) {
                this.widget.disable();
            }*/
        }
    },

    update: function(first) {
        if (this.tick == null) 
            return;
        var self = this, myTick = ++this.tick;
        fetchHints(this.options.hint,
            this.cm,
            this.options,
            function(data) {
                if (self.tick == myTick) self.finishUpdate(data, first);
            });
    },

    finishUpdate: function(data, first) {
        if (this.data)
            CodeMirror.signal(this.data, "update");

      var picked = (this.widget && this.widget.picked) || (first && this.options.completeSingle);
      if (this.widget) this.widget.close();

      this.data = data;

      if (data && data.list.length) {
        if (picked && data.list.length == 1) {
          this.pick(data, 0);
        } else {
          this.widget = new Widget(this, data);
          CodeMirror.signal(data, "shown");
        }
      }
    }
  };

  function parseOptions(cm, pos, options) {
    var editor = cm.options.hintOptions;
    var out = {};
    for (var prop in defaultOptions) out[prop] = defaultOptions[prop];
    if (editor) for (var prop in editor)
      if (editor[prop] !== undefined) out[prop] = editor[prop];
    if (options) for (var prop in options)
      if (options[prop] !== undefined) 
          out[prop] = options[prop];
      if (out.hint.resolve) out.hint = out.hint.resolve(cm, pos);
    return out;
  }

  function getText(completion) {
    if (typeof completion == "string") 
        return completion;
    else 
        return completion.text;
  }

    function buildKeyMap(completion, handle) {
        var baseMap = {
            Up: function() { handle.moveFocus(-1); },
            Down: function() { handle.moveFocus(1); },
            PageUp: function() { handle.moveFocus(-handle.menuSize() + 1, true); },
            PageDown: function() { handle.moveFocus(handle.menuSize() - 1, true); },
            Home: function() { handle.setFocus(0); },
            End: function() { handle.setFocus(handle.length - 1); },
            Enter: handle.pick,
            Tab: handle.pick,
            Esc: handle.close
        };

        var custom = completion.options.customKeys;
        var ourMap = custom ? {} : baseMap;

        function addBinding(key, val) {
            var bound;
            if (typeof val != "string")
                bound = function(cm) { return val(cm, handle); };
            // This mechanism is deprecated
            else if (baseMap.hasOwnProperty(val))
                bound = baseMap[val];
            else
                bound = val;
            ourMap[key] = bound;
        }

        if (custom)
            for (var key in custom)
                if (custom.hasOwnProperty(key))
                    addBinding(key, custom[key]);

        var extra = completion.options.extraKeys;
        if (extra)
            for (var key in extra)
                if (extra.hasOwnProperty(key))
                    addBinding(key, extra[key]);

        return ourMap;
    }

    function getHintElement(hintsElement, el) {
    while (el && el != hintsElement) {
      if (el.nodeName.toUpperCase() === "LI" && el.parentNode == hintsElement) return el;
      el = el.parentNode;
    }
  }

    function Widget(completion, data) {
        this.completion = completion;
        this.data = data;
        this.picked = false;
        var widget = this, cm = completion.cm;

        var hints = this.hints = document.createElement("ul");
        hints.className = "CodeMirror-hints";
        this.selectedHint = data.selectedHint || 0;

        var completions = data.list;
        for (var i = 0; i < completions.length; ++i) {
            var elt = hints.appendChild(document.createElement("li")), cur = completions[i];
            var className = HINT_ELEMENT_CLASS + (i != this.selectedHint ? "" : " " + ACTIVE_HINT_ELEMENT_CLASS);
            if (cur.className != null) className = cur.className + " " + className;
            elt.className = className;
            if (cur.render) cur.render(elt, data, cur);
            else elt.appendChild(document.createTextNode(cur.displayText || getText(cur)));
            elt.hintId = i;
        }

        var pos = cm.cursorCoords(completion.options.alignWithWord ? data.from : null);
        var left = pos.left, top = pos.bottom, below = true;
        hints.style.left = left + "px";
        hints.style.top = top + "px";
        // If we're at the edge of the screen, then we want the menu to appear on the left of the cursor.
        var winW = window.innerWidth || Math.max(document.body.offsetWidth, document.documentElement.offsetWidth);
        var winH = window.innerHeight || Math.max(document.body.offsetHeight, document.documentElement.offsetHeight);
        (completion.options.container || document.body).appendChild(hints);
        var box = hints.getBoundingClientRect(), overlapY = box.bottom - winH;
        var scrolls = hints.scrollHeight > hints.clientHeight + 1
        var startScroll = cm.getScrollInfo();

        if (overlapY > 0) {
            var height = box.bottom - box.top, curTop = pos.top - (pos.bottom - box.top);
            if (curTop - height > 0) { // Fits above cursor
                hints.style.top = (top = pos.top - height) + "px";
                below = false;
            } else if (height > winH) {
                hints.style.height = (winH - 5) + "px";
                hints.style.top = (top = pos.bottom - box.top) + "px";
                var cursor = cm.getCursor();
                if (data.from.ch != cursor.ch) {
                    pos = cm.cursorCoords(cursor);
                    hints.style.left = (left = pos.left) + "px";
                    box = hints.getBoundingClientRect();
                }
            }
        }
        var overlapX = box.right - winW;
        if (overlapX > 0) {
            if (box.right - box.left > winW) {
                hints.style.width = (winW - 5) + "px";
                overlapX -= (box.right - box.left) - winW;
            }
            hints.style.left = (left = pos.left - overlapX) + "px";
        }

        if (scrolls)
            for (var node = hints.firstChild; node; node = node.nextSibling) {
                node.style.paddingRight = cm.display.nativeBarWidth + "px";
            }

        this.keyMap = buildKeyMap(
            completion,
            {
                moveFocus: function(n, avoidWrap) { widget.changeActive(widget.selectedHint + n, avoidWrap); },
                setFocus: function(n) { widget.changeActive(n); },
                menuSize: function() { return widget.screenAmount(); },
                length: completions.length,
                close: function() { completion.close(); },
                pick: function() { widget.pick(); },
                data: data
            });

        cm.addKeyMap(this.keyMap);

        cm.on("keyup", function(cm, event) {
            // TODO: conflict with KeyMap
            if (event.keyCode === 38 || event.keyCode === 40) { 
                return;
            }
            if (cm.state.completionActive 
                && cm.state.completionActive.data 
                && cm.state.completionActive.data.list
                && cm.state.completionActive.data.list.length > 0) {
                var from = cm.state.completionActive.data.from;
                var to = cm.getCursor();
                var hintStart = cm.getRange(from, to).toLowerCase();
                if (hintStart) {
                    for (var j = 0; j < cm.state.completionActive.data.list.length; j++) {
                        var hint = cm.state.completionActive.data.list[j].text.toLowerCase();
                        if (hint.startsWith(hintStart)) {
                            widget.changeActive(j, true);
                            break;
                        }
                    }
                }
            }
        });

        if (completion.options.closeOnUnfocus) {
            var closingOnBlur;
            cm.on("blur",
                this.onBlur = function() { closingOnBlur = setTimeout(function() { completion.close(); }, 100); });
            cm.on("focus", this.onFocus = function() { clearTimeout(closingOnBlur); });
        }

        cm.on("scroll",
            this.onScroll = function() {
                var curScroll = cm.getScrollInfo(), editor = cm.getWrapperElement().getBoundingClientRect();
                var newTop = top + startScroll.top - curScroll.top;
                var point = newTop - (window.pageYOffset || (document.documentElement || document.body).scrollTop);
                if (!below) point += hints.offsetHeight;
                if (point <= editor.top || point >= editor.bottom) return completion.close();
                hints.style.top = newTop + "px";
                hints.style.left = (left + startScroll.left - curScroll.left) + "px";
            });

        CodeMirror.on(hints,
            "dblclick",
            function(e) {
                var t = getHintElement(hints, e.target || e.srcElement);
                if (t && t.hintId != null) {
                    widget.changeActive(t.hintId);
                    widget.pick();
                }
            });

        CodeMirror.on(hints,
            "click",
            function(e) {
                var t = getHintElement(hints, e.target || e.srcElement);
                if (t && t.hintId != null) {
                    widget.changeActive(t.hintId);
                    if (completion.options.completeOnSingleClick) widget.pick();
                }
            });

        CodeMirror.on(hints,
            "mousedown",
            function() {
                setTimeout(function() { cm.focus(); }, 20);
            });

        CodeMirror.signal(data, "select", completions[this.selectedHint], hints.childNodes[this.selectedHint]);
        return true;
    }

    Widget.prototype = {
    close: function() {
      if (this.completion.widget != this) return;
      this.completion.widget = null;
      this.hints.parentNode.removeChild(this.hints);
      this.completion.cm.removeKeyMap(this.keyMap);

      var cm = this.completion.cm;
      if (this.completion.options.closeOnUnfocus) {
        cm.off("blur", this.onBlur);
        cm.off("focus", this.onFocus);
      }
      cm.off("scroll", this.onScroll);
    },

    disable: function() {
      this.completion.cm.removeKeyMap(this.keyMap);
      var widget = this;
      this.keyMap = {Enter: function() { widget.picked = true; }};
      this.completion.cm.addKeyMap(this.keyMap);
    },

    pick: function() {
      this.completion.pick(this.data, this.selectedHint);
    },

    changeActive: function(i, avoidWrap) {
      if (i >= this.data.list.length)
        i = avoidWrap ? this.data.list.length - 1 : 0;
      else if (i < 0)
        i = avoidWrap ? 0  : this.data.list.length - 1;
      if (this.selectedHint == i) return;
      var node = this.hints.childNodes[this.selectedHint];
      node.className = node.className.replace(" " + ACTIVE_HINT_ELEMENT_CLASS, "");
      node = this.hints.childNodes[this.selectedHint = i];
      node.className += " " + ACTIVE_HINT_ELEMENT_CLASS;
      if (node.offsetTop < this.hints.scrollTop)
        this.hints.scrollTop = node.offsetTop - 3;
      else if (node.offsetTop + node.offsetHeight > this.hints.scrollTop + this.hints.clientHeight)
        this.hints.scrollTop = node.offsetTop + node.offsetHeight - this.hints.clientHeight + 3;
      CodeMirror.signal(this.data, "select", this.data.list[this.selectedHint], node);
    },

    screenAmount: function() {
      return Math.floor(this.hints.clientHeight / this.hints.firstChild.offsetHeight) || 1;
    }
  };

  function applicableHelpers(cm, helpers) {
      if (!cm.somethingSelected()) return helpers;
      var result = [];
    for (var i = 0; i < helpers.length; i++)
        if (helpers[i].supportsSelection) result.push(helpers[i]);
      return result;
  }

  function fetchHints(hint, cm, options, callback) {
    if (hint.async) {
        hint(cm, callback, options);
    } else {
        var result = hint(cm, options);
        if (result && result.then) result.then(callback);
        else callback(result);
    }
  }

  function resolveAutoHints(cm, pos) {
      var helpers = cm.getHelpers(pos, "hint"), words;
    if (helpers.length) {
      var resolved = function(cm, callback, options) {
        var app = applicableHelpers(cm, helpers);
        function run(i) {
            if (i == app.length) return callback(null);
            fetchHints(app[i],
                cm,
                options,
                function(result) {
                    if (result && result.list.length > 0) callback(result);
                    else run(i + 1);
                });
        }

          run(0);
      }
        resolved.async = true;
        resolved.supportsSelection = true;
        return resolved;
    } else if (words = cm.getHelper(cm.getCursor(), "hintWords")) {
      return function(cm) { return CodeMirror.hint.fromList(cm, {words: words}) }
    } else if (CodeMirror.hint.anyword) {
      return function(cm, options) { return CodeMirror.hint.anyword(cm, options) }
    } else {
      return function() {}
    }
  }

  CodeMirror.registerHelper("hint", "auto", {
    resolve: resolveAutoHints
  });

  CodeMirror.registerHelper("hint", "fromList", function(cm, options) {
    var cur = cm.getCursor(), token = cm.getTokenAt(cur);
    var to = CodeMirror.Pos(cur.line, token.end);
    if (token.string && /\w/.test(token.string[token.string.length - 1])) {
      var term = token.string, from = CodeMirror.Pos(cur.line, token.start);
    } else {
      var term = "", from = to;
    }
    var found = [];
    for (var i = 0; i < options.words.length; i++) {
      var word = options.words[i];
      if (word.slice(0, term.length) == term)
        found.push(word);
    }

    if (found.length) return {list: found, from: from, to: to};
  });

  CodeMirror.commands.autocomplete = CodeMirror.showHint;

  var defaultOptions = {
    hint: CodeMirror.hint.auto,
    completeSingle: true,
    alignWithWord: true,
    closeCharacters: /[\s()\[\]{};:>,]/,
    closeOnUnfocus: true,
    completeOnSingleClick: true,
    container: null,
    customKeys: null,
    extraKeys: null
  };

  CodeMirror.defineOption("hintOptions", null);
});
